1. Field of the Invention
The present invention relates to a semiconductor module, which includes an integrated circuit that encompasses at least one oscillator for generating a radar signal, and a rewiring layer for the external connection of the integrated circuit; it also has at least two antenna structures, which are integrated in the semiconductor module, for the transmission and/or reception of radar signals, at least one of the at least two antenna structures being connected to the integrated circuit. In particular, the present invention relates to such a semiconductor module for automotive radar applications. Furthermore, the present invention relates to a radar sensor having such a semiconductor module, and to an automotive radar system having a semiconductor module of this type.
2. Description of the Related Art
Radar sensors are used for measuring the distance and/or speed of objects. Known in particular are radar systems in which speeds and distances of multiple objects are recorded simultaneously. For example, vehicle speed controllers for vehicles equipped with a radar system for locating a vehicle driving ahead and for measuring the distance to this vehicle are known. Such a distance control system is also referred to as an ACC system (Adaptive Cruise Control).
To simplify the configuration of HF circuits for radar applications, integrated microwave circuits of the MMIC type (Microwave Monolithic Integrated Circuit) are increasingly used for the transmit and receive circuits.
Wafer assemblies are known in which the component is produced with a rewiring layer for an IC component at the wafer level. Such a wafer component assembly is also called an embedded grid array at the wafer level (eWLB, embedded wafer level ball grid array).
Published German patent application document DE 10 2010 001 407 A1 describes a semiconductor module in which antennas are integrated at the wafer level. The semiconductor module includes a first housing molding mass layer and an IC component having an integrated circuit in which the first housing molding mass layer is embedded. An intermediate layer includes a rewiring layer, which is connected to the IC component and used for the external connection of the IC component. An integrated antenna structure is situated within the intermediate layer and connected to the IC component. Such a semiconductor module may be produced with a degree of precision that is suitable for the high-frequency range of 77 GHz, for example. An eWLB semiconductor module of this type including antennas that are integrated into the housing is also referred to as an antenna in package (AiP). In one example, the integrated antenna structure is a patch antenna, and an additional second antenna structure in the form of a parasitic microstrip patch antenna is situated on the surface of the semiconductor module, the second antenna structure oscillating at a slightly lower frequency and thus having the capability of increasing the impedance width of the integrated antenna structures.